Tuesday, June 30, 2009

Automate Unit Test Execution

A lot of times, when doing TDD, we make small refactorings and then have to manually go ahead and run the tests to figure out whether the changes we made are consistent and have not broken the tests. Wouldn't it be good if the tests were run on each Save to ascertain that we have not broken any of the tests. This also lets us know which changes are the culprit. Using eclipse we can automate running the unit tests on each change and save we make. Following are the steps needed in order to accomplish this.
  1. Create a main class
import junit.framework.TestSuite;
import junit.textui.TestRunner;
public class TestBootstrap
public static void main(String[] args)
TestSuite testSuite=new TestSuite();

2. Create an ant build file

<target name="eclipse-test-runner">
<java classname="TestBootstrap" classpath="bin:libs/junit.jar"> <java> </target>

3. Create a Builder in eclipse
Open project properties: Right click project -> Propertie. Create new ant builder step after the Java Builder in eclipse: Builders -> new -> Ant Builder. Give your builder a nice name.
Main: Select the build file and the base directory
Targets: Select your ANT target for: “After Clean”, “Manual Build”, and “Auto Build” (most important) Build Options: Check “Specify working set” and select all of your source folders.
And thats all, now every time you save a file, eclipse will run the ant target specified in your build file, which incidentally calls your TestBootstrap's main and invoked all the tests.

Monday, June 15, 2009

Reading an RSS feed in groovy

Here's a small script to read RSS feeds from any site using groovy. You can customize it to read from multiple feeds by feeding the url's from a file etc.

def url='http://feeds.dzone.com/dzone/frontpage'
def channel=new XmlParser().parse(url).channel[0]
println channel.title.text()
println channel.link.text()
println channel.description.text()
println '\nStories:\n---------'
def items=channel.item
for(item in items){
println item.title.text()
println item.link.text()
println item.description.text()

Thursday, June 11, 2009

Google Wave - A First look

I took a look at the presentation of Google Wave, conducted by Lars Rasmussen and his technical team. Although its still in sandbox, it appears to be a very interesting product. The capabilities of what can be achieved in a browser are mind blowing. A very interesting point about Wave is that it would be open sourced. Primarily i think Google would need a lot of contributions from the community to really leverage the power which Wave promises. Wave brings the power of IM and email together and adds a different dimension to it. An early release of the wave API's are available .So go ahead and get your hands dirty. The API's available are the extension API's for building wave gadgets, robots and the Embed API's.

Fan -- Another New Java

Fan has recently been doing the rounds and i spent some time looking at it. It appears to be pretty much in the same space as Scala in most aspects. A deeper look at Fan reveals some interesting points. Similarity with Scala is it runs on the vm, has both dynamic and static typing, closures, mixins are built in etc etc. However a few interesting features in Fan over and above these are
1) Core support for the JVM, CLR and Javascript in the browser.
2) No support for global variables
3) Almost Erlang like concurrency semantics
4) Types are non nullable by default
5) Simpler namespaces and less verbose API's
6) JSON like serialization
On the while it appears has a groovy like simplicity with all the power of scala.

Wednesday, June 3, 2009

Proejct Euler Problem 1

Got to know about Project Eular.
So thought about posting a few solutions using groovy. For the 1st problem, the solution is pretty simple

def series3=0;
def series5=0;
def series15=0;
def result=series3 +series5 - series15

Export Data from Flat files to database:The Groovy way

Recently i was supposed to port a lot of data from flat files into a database. Looking at alternatives i thought it would be neat to accomplish the same using a small groovy script. Here's the crux of the script

def sql = groovy.sql.Sql.newInstance('jdbc:mysql://localhost:3306/test' ,
'root', ' ', 'com.mysql.jdbc.Driver' )
new File("C:/data/").eachFile{file->
def col1
def col2
def col3
def args=line.split(",")
INSERT INTO table (col1, col2, col3)
VALUES (${col1}, ${col2}, ${col3});

The emperor and me beaching

The Devil next door

Kaiser The Emperor